The following studies will be undertaken: (1) Studies of the phospholipid turnover, arachidonic acid release and certain prostaglandin formation will employ resting and activated mouse peritoneal macrophages, rabbit lung macrophages in which angiotensin convertase has been induced, and also human lung macrophages for control and diseased subjects. (2) Further purification of angiotensin convertase from mouse livers in schistosome infected mice.